Integrated sulfur recovery and hydrogen production process

ABSTRACT

H2 production, sulfuric acid and SO2 production process refers to an innovative process VIA the phenomena of the Sulfur-Iodine (S-I) thermochemical cycle. The process consist of the acid gas burner to burn all the acid gases with air, enriched air or oxygen and without using any fuel gas to produce SO2. The acid gases are normally processed in the prior arts of the sulfur recovery units. Iodine is used to produce the hydrogen. 
     A portion or all of the acid gases are sent to the acid gas burner in accordance with the present invention. 
     The present innovation not only produces hydrogen but also reduces the SO2 and CO2 emissions. 
     The produced SO2 is sent to other units to produce other fertilizer products and the produced CO2 is sent to CO2 removal or CO2 Liquefaction process. 
     The hydrogen is produced is used to supply the needs within the facility like hydrotreaters to reduce external import and to reduce the operating costs.

CROSS REFERENCE TO RELATED APPLICATIONS

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STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

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REFERENCE TO SEQUENCE LISTING

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REFERENCE TO A TABLE

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REFERENCE TO A COMPUTER PROGRAM LISTING COMPACT DISK APPENDIX

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BACKGROUND OF THE INVENTION

This disclosure relate the integration of sulfur recovery to producehydrogen, SO2, H2SO4, and fertilizer products. The present invention iscombination of prior arts for producing SO2 from the acid gasescontaining H2S is processed in the suitable acid gas burner incinerationwith the excess air/oxygen and without fuel. The present invention alsointroduces the new technology to produce large quantity of H2 VIA thephenomena of the Sulfur-Iodine (S-I) thermochemical cycle. Iodine isused to produce the hydrogen.

H2 production, sulfuric acid and SO2 production process refers to aninnovative process VIA the phenomena of the Sulfur-Iodine (S-I)thermochemical cycle. The process consist of the acid gas burner to burnall the acid gases with air, enriched air or oxygen and without usingany fuel gas to produce SO2.

The present invention objectives are not only to produce hydrogen butalso to produce SO2 that is converted to sulfuric acid or fertilizerproducts or to liquefied SO2 for other SO2 applications.

The other aspects of the present invention is to reduce CO2 emission andde-carbonization compare to prior arts of the commercial sulfur recoverytechnologies.

The present innovation can be applied to the gas plants, sour gas fielddevelopments, refineries, bio-refining, petrochemical plants, IGCC, LNGand any facilities that produce acid gases containing H2S.

In accordance with aspects of the present invention, full streams flowor a portion of one or both gases; amine acid gases and the sour waterstripper gases (SWS) are sent to the present innovative technology forprocessing, which these gas streams are normally processed in the Claussulfur recovery unit.

In other aspects of this innovation, the SO2 produced in the presentinvention can also be reacted with the SWS gas to produce ammoniumsulfate or ammonium thiosulfate (NH4)2S2O3 as fertilizer products, whichreduces the size of the Claus unit and ultimately to reduce or toeliminate SO2 and CO2 emissions.

DESCRIPTION OF THE RELATED ART

The prior arts; Sulfur plant operation is a very complicated andchallenging job. Acid gas feed to a sulfur plant usually includes widevariation in the volume and concentration of sulfur and other compounds,including a substantial amount of ammonia and amine acid gases in mostplants. Theoretically, control of the thermal stage(s) using air,enriched air or oxygen for conversion of H2S to SO2 has permitted someprocesses to obtain extremely high recovery of sulfur whether for the2:1 ratio for H2S to SO2 or for H2S-shifted operation. However, theunrecovered gases are sent to the incineration where requiressignificant fuel to combust the gas and the utility consumption in thetail unit are high and no hydrogen is produced.

In refineries they need to supply hydrogen for hydrotreater, some oftail gas processes and methane is normally used to generate hydrogen forusing in their different units, wherein, the new invention the requiredhydrogen can be produced to supply the need inside of the refineries andto eliminate using methane or other process for this purpose.

Producing hydrogen has been evaluated in different ways, however,economic is the main factor as some described below.

Natural Gas Reforming/Gasification: Synthesis gas a mixture of hydrogen,carbon monoxide, and a small amount of carbon dioxide is produced byreacting natural gas with high-temperature steam. The carbon monoxide isreacted with water to produce additional hydrogen. This method is thecheapest, most efficient, and most common. Natural gas reforming usingsteam accounts for the majority of hydrogen produced in the UnitedStates annually.

A synthesis gas can also be created by reacting coal or biomass withhigh-temperature steam and oxygen in a pressurized gasifier. Thisconverts the coal or biomass into gaseous components a process calledgasification. The resulting synthesis gas contains hydrogen and carbonmonoxide, which is reacted with steam to separate the hydrogen.

Electrolysis: An electric current splits water into hydrogen and oxygen.If the electricity is produced by renewable sources, such as solar orwind, the resulting hydrogen will be considered renewable as well, andhas numerous emissions benefits. Power-to-hydrogen projects are takingoff, using excess renewable electricity, when available, to makehydrogen through electrolysis.

Renewable Liquid Reforming: Renewable liquid fuels, such as ethanol, arereacted with high-temperature steam to produce hydrogen near the pointof end use.

Fermentation: Biomass is converted into sugar-rich feed-stocks that canbe fermented to produce hydrogen.

High-Temperature Water Splitting: High temperatures generated by solarconcentrators or nuclear reactors drive chemical reactions that splitwater to produce hydrogen.

In the patent (U.S. Pat. No. 11,104,574 B2, dated August 2021) describesHYDROGEN SULFIDE MEDIATED WATERSPLITTING FOR HYDROGEN GAS AN SULFURDIOXIDE PRODUCTION. Wherein, there is no acid gas burner incineration isused, in addition, in real operation, the acid gas is not pure H2S andcontains other components and impurities from upstream units that causesside effects and instability in the process. The other disadvantage ofthis scheme is that only ⅓ of H2S is converted to sulfur and ⅔ isconverted to SO2 and requires significant heat for decomposition and asthe results, the hydrogen production is reduced. The chemical reactionrepresents H2S+2H2O→SO2+3H2.

In additions, U.S. Pat. No. 4,258,026 A, by March 1981 O'Keefe relatesto the I2 decompositions and the chemistry and it is not relevant.

Other prior related arts refers to numerous studies have been conductedrelated to sulfur-Iodine and H2 production in nuclear plants, which theevaluations are based on pure H2S or minor impurities.

All of studies have a common basis and conclusion whereas, refers to ahydrogen economy will need significant new sources of hydrogen. Unlesslarge-scale carbon sequestration can be economically implemented, use ofhydrogen reduces greenhouse gases only if the hydrogen is produced withnon-fossil energy sources. Nuclear energy is one of the limited optionsavailable. One of the promising approaches to produce large quantitiesof hydrogen from nuclear energy efficiently is the Sulfur-Iodine (S-I)thermochemical water-splitting cycle, driven by high temperature heatfrom a nuclear reactor.

The study was conducted by Benjamin Russ, Dated June 2009 for the USDepartment of Energy Nuclear plant, another study was conducted byKentucky University, L. C. Brown, dated 2003, and the study wasconducted by DOE Hydrogen program and Sandia National Labs by P.Pickard, dated May of 2005 using nuclear energy. The present inventionrefers to the gases are processed in the sulfur recovery units, as knownas amine acid gases and sour water stripper gases.

In accordance with the aspects of the present innovation, the acid gasburner is designed to combust all the components in the acid gases andis converted to combusted products that prevent side effects, sidereactions, and to establish stable operation based on real data. As theresults, higher quantity of H2 is produced.

In accordance with the aspects of the present innovation, full acidgases stream or portion of the gases is processed and the verity ofdifferent products is produced.

The present disclosure reduces the energy and fuel consumptions, and theconsumptions of other utilities such as cooling water, steam, andrefrigeration system are reduced or eliminated.

The present disclosure reduces CO2 emission in addition to sulfuremission while the significant quantity of H2 is also produced.

BRIEF SUMMARY OF THE INVENTION

This disclosure relates generally to Process the acid gases containingH2S and the sulfur compounds that is normally processed in the Clausunit, now to produce SO2, and H2 VIA the sulfur-Iodine thethermochemical cycle process.

The present invention relates to a process for acid gases that arecombusted in the acid gas burner with excess air/oxygen to achievecomplete combustion.

The burner are suitable to combust both amine acid gases and the sourwater stripper gases above 900 C. The burner is selected with the propermaterial of construction and the proper refractory to handle such hightemperature and the adequate residence time.

The acid gas streams that normally flow to the Claus unit at leastcontaining H2S, COS, N2, HCN, phenol, CS2, CO2, H20, hydrocarbons,mercaptans, sulfur vapors and high ammonia content and any other sulfurcompounds. Wherein, the sulfur compounds are converted to SO2 andammonia is converted to nitrogen and water.

In the prior arts wherein, all the tail gas thermal incinerationrequires fuel gas to establish the stable combustion and to achieve theadequate combustion temperature, while in the present invention H2S withair or oxygen is combusted to produce SO2 without using fuel gasresulting lower CO2 emission.

Therefore, in the present disclosure, a portion of the acid gases or100% of the acid gas that normally flows to the Claus; known as sulfurrecovery process is sent to the new process that represents theinnovative art, wherein, the acid gases is processed.

In the description of the present innovation, sometimes relevant part ofprior arts are referenced or discussed in this application forcomparison and sake of clarity.

In summary, the present invention comprises several steps for producingSO2 and H2 from the acid gases that containing sulfur compounds such asH2S and it is incinerated in the acid gas burner using only air andoxygen. Then the combusted gas is cooled off in two waste heat boilersto recover the heat wherein, in contact with Iodine, HI is converted toI2 and H2. Wherein, H2 and SO2 are separated as products.

step 1) In accordance with first aspects of the present invention,providing an acid gas stream that is normally processed in the Clausunit, into present invention; the acid gas burner incineration unitwhere H2S and all other sulfur compounds and ammonia, hydrocarbons inthe feed reacts with excess air/oxygen to produce SO2, CO2 and otherminor products; based on the reaction of H2S+3/2O2→SO2+H2O and 2NH₃+3/2O₂→N₂+3H₂O.

step 2) In accordance with second aspects of the present invention, thecombusted gas mixture from step 1 consists of SO2, 02,N2, H20 and SO3 iscooled off in the first waste boiler or H2SO4 Vaporizer and theenergy/heat is produced is used in the process to heat up other streamsor steam can be produced,

step 3) In accordance with third aspects of the present invention, thecombusted gas mixture from step 2 is further cooled off and quenched inthe tube side of a exchanger and is sent to a reactor;

step 4) In accordance with forth aspects wherein, in the shell side ofthe step 3 exchanger, I2, HI and water is added to heat up the mixtureand the chemical reaction occurs and H2 and I2 is produced then themixture is sent to a 3 phase separator to condense H2O which is recycledto step 5, wherein, H2 is separated from I2, and H2 is one of theproduct from the present innovation;

Step 5) In accordance with fifth aspects of the present invention,wherein, the cooled gas mixture, SO2, O2,N2, H2O and SO3 has twochoices;

-   -   (1) a portion of the stream is sent to other units as SO2        product for other applications as valuable fertilizer or other        products or SO2 is liquefied;    -   (2) a portion or the full stream is sent to the reactor with I2        and recycled H2O from step 4, to have another reaction at 120 C;        wherein, SO2 reacts with I2 accordance to equation of to produce        sulfuric acid and HI: SO2+I2+2H2O→H2SO4+2HI;

Step 6) In accordance with sixth aspects of the present inventionwherein, the cooled gas from the reactor enters a quench column where N2and CO2 is separated from the mixture, and is sent to CO2 removal or CO2liquefaction unit, the bottom of the quench column consists of H2SO4,H2o, IH and HI flows to liquid-liquid contactor to separate H2SO4 fromIH and I2 and recycled to step 4;

Step 7) In accordance with seventh aspects of the present inventionH2SO4 from step 6, bottom of the liquid-liquid contactor is sent to asulfuric acid concentration to concentrate the H2SO4 as another producton the present invention by using steam reboiler as desired and thewater is removed.

In accordance with the present innovation, the acid gas containing H2Sand sulfur compounds that are normally processed in the Claus sulfurrecovery unit, is processed in the acid gas incineration burner toproduce SO2 and to produce large quantity of hydrogen with theSulfur-Iodine (S-I) thermochemical cycle.

The type of acid gases are processed in the prior arts of the Clausrecovery are varied, sometime the acid gas is rich with H2S andsometimes is lean with H2S. For cases dealing with lean H2S andimpurities like mercaptan or heavy hydrocarbons, processing lean gasesare very difficult to achieve stable operation, and the overall recoveryis low and SO2 and CO2 emissions are high, the present invention, solvesthis problem and the requirements of the acid gas enrichment iseliminated. The present invention is suitable for any acid gascompositions rich or lean H2S concentration.

According to public data, Sulfuric acid is decomposed at hightemperature and hydrogen iodide at lower temperatures. There aresignificant chemical separations associated with each chemical reaction.Water is the primary solvent in the system and iodine is a veryimportant solvent in the reaction.

Sulfuric acid cannot be separated from hydrogen iodide, by thermalmeans, without reversing the equilibria. This separation is readilyaccomplished in, the presence of a large excess of iodine, with theformation of two immiscible liquid phases, a light H2SO4/H20 phase and aheavy HI/I2/H2O phase. Cost effective hydrogen production, using thesulfur-iodine cycle, requires that hydrogen be generated from the heavyphase efficiently and without excessive capital requirements.

The reaction, where SO2 and 12 are added to water to produce H2SO4 andHI, operates with excess water and also with excess iodine to allowseparation of the H2SO4 and HI, and includes a boost reaction toincrease the concentration of the H2SO4 in water. The H2SO4decomposition section includes concentration and decomposition torecover the SO2 and produce O2. The HI decomposition section chosen inthis study uses reactive distillation of the HI, I2, H2O mixture torecover I2 and produce H2, but has a large recirculation flow back tothe reaction section.

The sulfur-iodine thermochemical cycle generates hydrogen through thechemical reactions:

H2S+3/2O2→SO2+H2O 900° C.

2H2O+SO2+I2→H2SO4+2HI 120° C.

2HI→H2+I2 300-450° C.

Overall Reaction:

H2S+3/2O2+H2O→H2+H2SO4

In the present innovation wherein, the sulfur-Iodine (S-I)thermochemical cycle is used to produce hydrogen.

BRIEF DESCRIPTION OF THE DRAWINGS

The following figures are part of the present disclosure and areincluded to further illustrate certain aspects of the present invention.Aspects of the invention may be understood by reference to one or morefigures in combination with the detailed written description of specificembodiments presented herein. These figures present the combinations ofthe modified, upgraded, and revamped of the prior arts plus the presentinvention. A block flow diagram is shown as FIG. 1 consists of thepresent innovation scheme.

While the inventions disclosed herein are susceptible to variousmodifications and alternative forms, only a few specific embodimentshave been shown by way of example in the drawings and are described indetail below. The figures and detailed descriptions of these specificembodiments are not intended to limit the breadth or the scope of theinventive concepts or the appended claims in any manner. Rather, thefigures and detailed written descriptions are provided to illustrate theinventive concepts to a person of ordinary skill in the art and enablesuch person to make and use the inventive concepts.

FIG. 1 consists of drawings, wherein, represents the overall block flowdiagram for the present innovation for the major equipment.

FIG. 2 consists of drawings, wherein, the amine acid gases, and the sourwater stripper acid gases, from the oil and gas facilities are processedin the sulfur recovery, tail gas treating based on the prior arts.

FIG. 3 consists of drawings, wherein, represents how the presentinvention can be implemented with the prior arts. Taking full or portionof the acid gases that are currently processed in the sulfur recoveryunit prior arts, to the present invention. Wherein, to produce Hydrogen,to reduce the fuel gas consumption, to reduce SO2 and CO2 emissions andto produce the new products. While the hydrogen as a major product inthe present invention is produced represents a new H2 source supplyingthe hydrogen demand to different units such as hydrotreaters, which isresulting to reduce external supply and to reduce the operating costs.

FIG. 4 -A represents the current invention wherein, provides the detailsof some of the equipment of the FIG. 1 . FIG. 4 -A shows the mainfurnace where the acid gases are processed and the combustion productsare cooled in the waste heat boiler and the additional cooler beforesending to the FIG. 4 -B. Basically, FIG. 4 -A shows the function of themajor equipment of the present invention, it shows the 3-phase separatorequipment the separate the mixture that comes from the FIG. 4 -B.

FIG. 4 -B represents the current invention wherein, provides the detailsof the remaining equipment of the FIG. 1 . FIG. 4 -B shows the reactor,quench column, H2SO4 concentrator and liquid-liquid contactor to processthe gases from FIG. 4 -A.

FIG. 4 -A and FIG. 4 -B together represents the main and actualequipment of the current invention wherein, it is shown in FIG. 1 (FIG.1 ) as the block flow diagram in a compact and summarized format.

DETAILED DESCRIPTION OF THE INVENTION

One or more illustrative embodiments incorporating the inventiondisclosed herein are presented below. Not all features of an actualimplementation are described or shown in this application for the sakeof clarity.

It is understood that in the development of an actual embodimentincorporating the present invention, numerous implementation-specificdecisions must be made to achieve the developer's goals, such ascompliance with system-related, business-related, government related andother constraints, which vary by implementation and from time to time.While a developer's efforts might be complex and time-consuming, suchefforts would be, nevertheless, a routine undertaking for those ofordinary skill the art having benefit of this disclosure.

In general, terms, Applicant has created new processes for the hydrogenproduction with the integration of the sulfur recovery unit.

The present invention relates to processes to produce hydrogen, SO2 andother relevant products to also reduce SO2 and CO2 emission, the newinvention applies to onshore and offshore applications; refineries, gasplants, IGCC, gasification, coke oven gas, mining and smelters sour gasfield developments and flue gas desulfurization, wherein, the acid gasescontain H2S and sulfur compounds.

In accordance with aspects of the present invention, it is an object ofthe present disclosure to provide a process to produce hydrogen, and SO2to reduce SO2 and CO2 emission and economically acceptable for, presentday industrial operations and higher safety standard.

Another object is to provide such a process, which can toleratevariances in operating conditions within a given range without majorequipment adaptations. A further object is to provide a process, whichcan be utilized in co-acting phases to provide, at acceptable economics,the capacity required in present-day industrial operations, easy tooperate and more reliable and robust operation.

In the discussion of the Figures, the same or similar numbers will beused throughout to refer to the same or similar components. Not allvalves and the like necessary for the performance of the process havebeen shown in the interest of conciseness. Additionally, it will berecognized that alternative methods of temperature control, heating andcooling of the process streams are known to those of skill in the art,and may be employed in the processes of the present invention, withoutdeviating from the disclosed inventions. Finally, the present inventionis a polisher to existing arts therefore, the existing arts and theirvariations scheme of existing arts are discussed where their FEED streamenters the present invention of acid gas burner incineration.

The figures illustrate steam reheaters that heats up the gas by usingsteam, however, any suitable heat exchanger, using different heatingmedia, or fired reheaters using natural gas or acid gas, and hot gasbypass maybe employed in this service.

The figure illustrates a waste heat boiler that produces steam, however,any suitable heat exchanger, such as a water heater, steam superheateror feed effluent exchanger may be employed in this service.

The acid gas burner incineration may have multiple burner to prevent NOxformation during the ammonia burning with intercooling system betweenthe acid gas burners and with mixing devices, checker wall or choke ringor vector wall to create the turbulent velocity of gas for a bettermixing and to prevent cold spot and condensation. In addition, thechecker wall near the tube sheet of the waste heat boiler maybe added toprotect the tube sheet from the heat radiation from the burner.

In accordance to this invention; the prior arts; sulfur recovery unitsmay be modified to improve the operation wherein, the present innovationis integrated.

Once again, since the prior arts provides feed gas stream to the presentinvention;

The prior arts are upgraded, modified, revamped, and optimized by addingrelated equipment, adding piping, adding recycle from the presentinvention, changing the catalysts, adding instrumentation, modifiedexisting equipment to be suitable.

In the prior arts; the last condenser may be modified or replaced as atleast one heat exchanger or multiple heat exchangers, dual condensers orcombination of water coolers and air coolers to achieve maximum sulfurcondensation and sulfur recoveries.

The new invention comprises that SO2 and CO2 emissions is reducedsignificantly, while hydrogen is also produced.

All the heat exchangers defined in this process can be of any type ofcommercial exchangers such as but not limited to fired heaters, shelland tube, plate and frame, air cooler, water cooler, boiler type, or anysuitable exchangers.

All required control systems in the prior and new arts are defined basedon the latest commercial control systems including but not limited tolocal panel, DCS control room, burner management systems in the sulfurplant, switching valves sequencer control systems, reactors, condensers,incineration and adsorbers and all necessary equipment in thisinnovation.

The sequence runs fully automatically without requiring any operatoraction.

Turning now to the FIG. 1 consists of the block flow diagram of thepresent invention wherein, the major chemical reaction is also shown ineach box to facilitate the description in FIGS. 4 -A and 4-B.

FIG. 2 consists of the prior arts in the sulfur recovery units, wherein,the amine acid gases from refineries hydrotreaters, coker units or sourgas processing, petrochemicals, power plants and IGCC and LNG and miningand minerals are processed. The sour water stripping gas are known asphenolic, and nonphenolic SWS gases from one stage or 2 stage sour waterstrippers are also processed in the prior arts of sulfur recovery unitsaccording to Claus reaction and sulfur is produced. Two streams shown onFIG. 2 , represents the amine acid gases and the sour water stripperacid gases.

The unrecovered H2S and the sulfur compounds from the prior arts aresent to the prior art incineration and using significant amount of fuelto convert the sulfur compounds to SO2. While the fuel gas needed due tolow H2S concentration and burning fuel gas burning produces significantCO2 that is currently emitted to the atmosphere. If SO2 level is inacceptable range of the local regulations then SO2 and CO2 are bothemitted. If SO2 level is not in the acceptable range of the localregulations, then SO2 is absorbed by Caustic, SETR process or others,but the CO2 is still emitted.

In accordance with the present invention, if the acid gases are burnedin the acid gas burner first, then since the H2S concentration is high,there is no need to burn the fuel gas, the CO2 emission is reduced andthe cost of fuel gas is eliminated. In addition, SO2 emission is reducedand the key advantage is hydrogen is also produced which is another costsaving.

FIG. 3 consists of the combinations of the prior arts and the presentinvention. Wherein, a portion or the entire acid gases streams iscurrently processed in the prior art of the sulfur recovery is sent tothe present invention. The acid gases are processed in the presentinvention and hydrogen is produced and the CO2 and SO2 emission isreduced or eliminated.

Turning now to the current invention that consists of two pages as FIG.4 -A and FIG. 4 -B.

Iodine is used as a solvent to produce H2, H2SO4 and SO2 VIA thesulfur-Iodine thermochemical cycle, wherein, Iodine is regenerated andreused in the process.

The amine acid gases, the sour water stripping gas and any other ventstreams that contents the sulfur compounds streams 51,52 and 53 flows tothe acid gas burner, 30 and the air stream 54 from the air blower 31,flows to the acid gas burner, 30 as shown on FIG. 4 -A.

The acid gas burner consists of the proper material of construction withthe refractory inside to protect the metal at high combustiontemperature ranging 900 C to 2000 C with 100% stoichiometry and excessoxygen to convert all of the sulfur compounds to SO2. To dissociate NH3,HCN, phenol and the components from the sour water stripping gas towater and nitrogen and the vent stream containing sulfur vapor and H2Sto SO2.

The acid gas burner incineration consists of a suitable refractory andmixing devices such as choke ring, checker wall or vector wall toprotect the tube sheet of the waste heat boiler from the heat radiationfrom the burner.

The acid gas burner, 30 can use air, enriched air with oxygen or highlevel of oxygen to the burner.

The burner is one to ten burner stages and depends on the acid gases tothe burner, for cases NH3 is present, the configuration of staged burneror multiple burner is used to prevent NOx formation. High intensityburner operates effectively by using multiple burners and multiplecooling as WHB to achieve less than 20 ppmv of NOx according to thelatest air quality regulations.

Due to high H2S concentration of the acid gases to the burner, usingfuel to the acid gas burner is eliminated wherein, the present inventionreduces CO2 emission.

In accordance to present invention, wherein, the acid gas feed streamsto the acid gas burners consists one to 10 streams.

In accordance to present invention, wherein, Iodine is introduced as asolvent to produce H2, H2SO4 and SO2 VIA the sulfur-Iodinethermochemical cycle, wherein, Iodine is regenerated and reused in theprocess.

In accordance to present invention, wherein, the reaction temperature ofHI to produce H2 as the product is preferable at 450 C and from 300 C to500 C.

In accordance to present invention, wherein, the reaction temperature ofSO2 with H2O with I2 present in the reactor is preferable at 120 C from100 C to 200 C.

In accordance to present invention, wherein, the acid gas feed streamspressure to the acid gas burner is from 0.5 bar to 10 bar.

In accordance to present invention, wherein, the internal of the quenchcolumn, and the liquid-liquid contactor is high performance tray orpacking.

In accordance to present invention, wherein, the produced H2SO4 isconcentrated in the concentration column to achieve high purity ofmarket grade H2SO4.

The combusted products from the acid gas burner 30, flows to the wasteheat boiler, WHB 1, 32 to recover the combustion heat by producing HPsteam or is used as a sulfuric acid vaporizer to vaporize some H2SO4,stream 67 and to recycle to the acid gas burner.

In accordance to present invention, wherein, a slip stream of producedH2SO4 is recycled to the acid gas burner through H2SO4 vaporizer.

The combusted cooled gas, stream 55 contains SO2, H2O, O2, N2 and H2SO4,enters tube side of WHB 2, 33 to cool the gas further and the outlet ofWHB 2, 33 stream 56 enters the reactor.

The shell side of WHB 2, 33 receives H2O, I2 and HI as stream 65,wherein, the chemical reaction of 2HI→H2+I2 at 450 C with 3 phasesmixture wherein, enters a 3 phase separator vessel, wherein, H2 isseparated as the hydrogen product stream 60. Water is separated asstream 58 as recycle water. I2 is also separated as stream 57 to thereactor.

The hydrogen production is accordance on the present invention VIA thephenomena of the Sulfur-Iodine (S-I) thermochemical cycle.

The produced hydrogen can be used to supply the need within thefacilities like hydrotreater units, and to eliminate the import of theexternal supply and to reduce the operating costs.

A portion of stream 56 can be sent to other units to produce otherproducts like fertilizer products that are used in the agriculturalindustry or to process SO2 to liquefied SO2.

Streams 56, 57 and 58 flows to the reactor 35, refers to FIG. 4 -B,wherein, the reaction occurs SO2+I2+2H20→H2SO4+2HI at temperature of 120C.

All the sulfur compounds are converted to SO2, wherein, the SO2 emissionis eliminated.

The mixture leaving the reactor stream 61 enters the quench column 36,to cool the mixture using air/water cooler not shown.

CO2 and N2 stream 62 is separated and is sent to CO2 liquefaction systemor CO2 removal.

The liquid stream 64, from the bottom of the quench column 36, consistsof H20, H2SO4, I2 and IH enters the liquid-liquid contactor 38, toseparate H2SO4 from the I2 and IH. The recovered I2 and IH stream 65 isrecycled back to WHB 2 as the thermochemical agent.

The sulfuric acid stream 66 flows to the sulfuric acid concentrationunit 39, to concentrate the H2SO4 by removing water using reboiler asmedia.

Stream 70 represents sulfuric acid as another product.

In summary, the present invention, introduces a process to produce H2,produce SO2, produce H2SO4, while CO2 and SO2 emission is reduced oreliminated. The integration of sulfur recovery prior arts with thepresent invention produces H2 a valuable product, while SO2 and CO2emissions are lowered or eliminated. The produced SO2 and CO2 isliquefied to use in other industries.

All of the compositions, methods, processes and/or apparatus disclosedand claimed herein can be made and executed without undueexperimentation in light of the present disclosure. While thecompositions and methods of this invention have been described in termsof preferred embodiments, it will be apparent to those of skill in theart that variations may be applied to the compositions, methods,processes and/or apparatus and in the steps or sequence of steps of themethods described herein without departing from the concept and scope ofthe invention.

Additionally, it will be apparent that certain agents which are bothchemically and functionally related may be substituted for the agentsdescribed herein while the same or similar results would be achieved.All such similar substitutes or modifications apparent to those skilledin the art are deemed to be within the scope and concept of theinvention. The disclosed and undisclosed embodiments are not intended tolimit or restrict the scope or applicability of the invention conceivedof by the Applicant, but rather, in conformity with the patent laws,Applicants intends to protect all such modifications and improvements tothe full extent that such falls within the scope or range ofequivalents.

We claim:
 1. The present invention of H2 production, SO2 and H2SO4production steps introduces using the Sulfur-Iodine (S-I) thermochemicalcycle and the acid gas burner to process the acid gases that areprocessed in the prior arts of Claus sulfur recovery and tail gastreating unit, with combinations of necessary modifications to the priorarts wherein, a portion of the acid gases feed is routed to the presentinvention acid gas burners wherein, first the sulfur compounds, and theammonia gases are combusted with air or oxygen and without using anyfuel gas and then the combusted gases in contact with Iodine produceshydrogen and the remaining of SO2 is converted to the sulfuric acid oris sent to other units to produce other products, the Iodine as thecatalyst agent is recovered and re-used in the present invention:step 1) providing acid gas stream(s) from the amine acid gas and sourwater stripping gas that is normally processed in prior arts of Claussulfur recovery unit into properly designed acid gas burner or stagedburners, receiving air, enriched air or oxygen and without any fuel gasto combust all the combustible components to SO2, and other inert gasesnitrogen, CO2, N2, water and excess oxygen operating at a very hightemperature; step 2) when the gases are fully combusted in the acid gasburner(s), the combusted gas containing, SO2, CO2, N2, H2O, O2 and SO3or H2SO4 is sent to the waste heat boiler to generate HP steam or toH2SO4 vaporizer exchanger to recover the heat and to cool of thecombusted gas and vaporize a slim stream of H2SO4; step 3) the combustedgas mixture from step 2 is further cooled off and quenched in the tubeside of a exchanger and is sent to a reactor; step 4) in the shell sideof the step 3 exchanger, I2, HI and water is added to heat up themixture and the chemical reaction occurs and H2 and 12 is produced thenthe mixture is sent to a 3-phase separator to condense H2O which isrecycled to step 5, wherein, H2 is separated from I2, and H2 is one ofthe product from the present innovation; step 5) wherein, the cooled gasmixture, SO2, O2, N2, H2O and SO3 has two choices; (a) a portion of thestream is sent to other units as SO2 product for other applications asvaluable fertilizer or other products or SO2 is liquefied; (b) a portionor the full stream is sent to the reactor with I2 and recycled H2O fromstep 4, to have another reaction at 120 C; wherein, SO2 reacts with I2accordance to equation of to produce sulfuric acid and HI; Step 6)wherein, the cooled gas from the reactor enters a quench column where N2and CO2 is separated from the mixture, and is sent to CO2 removal or CO2liquefaction unit, the bottom of the quench column consists of H2SO4,H2o, IH and HI flows to liquid-liquid contactor to separate H2SO4 fromIH and I2 and recycled to step 4; Step 7) wherein, H2SO4 from step 6,bottom of the liquid-liquid contactor is sent to a sulfuric acidconcentration to concentrate the H2SO4 as another product on the presentinvention by using steam reboiler as desired and the water is removed.and wherein, said process produces H2, SO2 and H2SO4 as the productsmainly reduce importing of hydrogen and sulfuric acid to a facility andwherein, SO2 emission is eliminated, while CO2 emission is reduced andrecovered and sent to other unit.
 2. The process of claim 1, wherein,the acid gas streams flow to the high intensity acid gas burner at leastcontaining H2S, COS, N2, HCN, phenol, CS2, CO2, H2O, hydrocarbons, H2SO4mercaptans, sulfur vapors and high ammonia content and any other sulfurcompounds.
 3. The process of claim 1, wherein, the acid gases flow tothe acid gas burner consists of lean or rich H2S, NH3, mercaptans,sulfur vapors and all other sulfur compounds at all level ofconcentrations are processed directly in the acid gas burner achieve anstable operation without any requirement of the acid gas enrichmentunit.
 4. The process of claim 1, wherein, the acid gas burner consistsof one to 10 burners to establish staged combustions of the acid gasesand cooling between burners to prevent NOx formation.
 5. The process ofclaim 1, wherein, the acid gas burner combustion temperature operates at900 C to 2000 C to ensure full combustions of all acid gas feed streamswith excess oxygen.
 6. The process of claim 1, wherein, air stream,enriched air or oxygen enrichment stream is added to the acid gas burnerto combust the acid gas feed streams.
 7. The process of claim 1,wherein, the acid gas burner is designed with the proper material ofconstruction and is equipped with the advanced refractory lining toprotect the metal from exposing to high temperature.
 8. The process ofclaim 1, wherein, the acid gas burner and incineration is equipped withchoke ring, checker wall or vector wall to protect the downstreamequipment, waste heat boiler or a exchanger from direct radiation fromacid gas burners.
 9. The process of claim 1, wherein, the acid gas feedstreams to the acid gas burners consists one to 10 streams.
 10. Theprocess of claim 1, wherein, waste heat boiler or exchanger after theacid gas burners is one to 10 commercial waste heat boilers, condensersor exchangers.
 11. The process of claim 1, wherein, Iodine is introducedas a solvent to produce H2, H2SO4 and SO2 VIA the sulfur-Iodinethermochemical cycle, wherein, Iodine is regenerated and reused in theprocess.
 12. The process of claim 1, wherein, the reaction temperatureof HI to produce H2 as the product is preferable at 450 C and from 300 Cto 500 C.
 13. The process of claim 1, wherein, the reaction temperatureof SO2 with H2O with I2 present in the reactor is preferable at 120 Cfrom 100 C to 200 C.
 14. The process of claim 1, wherein, the acid gasfeed streams pressure to the acid gas burner is from 0.5 bar to 10 bar.15. The process of claim 1, wherein, the produced CO2 is sent to otherunits for CO2 recovery or CO2 liquefaction unit.
 16. The process ofclaim 1, wherein, the produced SO2 is sent to other unit to produceother products or liquefied SO2.
 17. The process of claim 1, wherein,the sources of the acid gas stream are refining, gas plants, sour gasfield developments, LNG, IGCC, power plants, mining and smelters,onshore and offshore, and petrochemicals that consisting of H2S streams;wherein, H2S and sulfur compounds come from hydrotreater or coker units,or gas plants or sour gas field developments amine units and H2S and NH3come from one stage or 2 stage sour water strippers system eitherphenolic and non-phenolic systems.
 18. The process of claim 1, wherein,the internal of the quench column and the liquid-liquid contactor ishigh performance tray or packing.
 19. The process of claim 1, wherein, aslipstream of produced H2SO4 is recycled to the acid gas burner throughH2SO4 vaporizer.
 20. The process of claim 1, wherein, the produced H2SO4is concentrated in the concentration column to achieve high purity ofmarket grade H2SO4.